Effect of diet on urinary excretion of unconjugated catecholamines and some of their metabolites in healthy control subjects and depressed patients

Moleman, P.

doi:10.1016/0009-8981(90)90230-p

Cited by 19 publications

(9 citation statements)

References 10 publications

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“…193,194 Free metadrenalines measured in plasma by HPLC -EC were observed to provide diagnostic sensitivities and speci¢cities as high as 100% and 89%, respectively, for detecting phaeochromocytoma. 87,130 At present, however, measurement of plasma metadrenalines is not widely available and the estimation of catecholamines and metabolites such as metadrenalines in urine collections is the mainstay of initial biochemical investigations. Plasma catecholamine measurements have limited diagnostic usefulness.Whilst plasma samples may be more convenient, the di¤culties associated with the collection of such samples and the limitations of basal plasma catecholamines to detect phaeochromocytoma are widely recognized.…”

Section: Phaeochromocytomamentioning

confidence: 99%

“…87 Historically, the spectrophotometric method described by Pisano was extensively used to measure total metadrenalines, i.e. the combined concentration of both normetadrenaline and metadrenaline in urine samples.…”

Section: Analysis Of Urinary Normetadrenaline and Metadrenalinementioning

confidence: 99%

“…28,136 At present, however, the question concerns not the choice of method but whether the measurement of plasma unconjugated or plasma total metanephrines represents the optimum biochemical approach for the diagnosis of phaeochromocytoma. 87,137,138 Plasma total metadrenalines have been determined after acid hydrolysis or enzymatic deconjugation with sulphatase to release sulphate-conjugated metabolites. 89,129,130,133 This produces plasma total concentrations some 20 -30-fold higher than free concentrations, thus making their estimation less technically demanding.…”

Section: Analysis Of Plasma Normetadrenaline and Metadrenalinementioning

confidence: 99%

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Measurement of catecholamines and their metabolites

2004

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Analysis of the low levels of catecholamines and metabolites in tissue and biological uids has necessitated the use of highly sensitive analytical techniques. Earlier procedures utilizing radioenzymatic and immunological assays, gas chromatography or uorimetry have generally been superseded by highly sensitive and selective chromatographic methods utilizing electrochemical or uorimetric detection. The development of high-performance liquid chromatography (HPLC) methods for the measurement of plasma metadrenalines and the combination of HPLC with tandem mass spectrometry provides additional procedures with minimum interference from drugs and drug metabolites. This review summarizes the methodology currently available for the measurement of catecholamines and metabolites in plasma and urine, the in uence of sample collection protocols and the clinical application of the methods for the biochemical detection of catecholamine-secreting tumours.

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Section: Phaeochromocytomamentioning

confidence: 99%

Section: Analysis Of Urinary Normetadrenaline and Metadrenalinementioning

confidence: 99%

Section: Analysis Of Plasma Normetadrenaline and Metadrenalinementioning

confidence: 99%

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Measurement of catecholamines and their metabolites

2004

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“…samples from eight subjects by the method described. The excreted amounts of metanephrines in seven of them was either physiological or somewhat greater if compared with values reported by other laboratories (2,16,27,28) For the quantification of Pheochromocytoma is rather rare so that only one such sample has been obtained. In this case the excretion of NMN was more than fifteenfold greater compared to the normal values.…”

mentioning

confidence: 86%

“…The speed and resolution now available in HPLC combined with the elimination of troublesome derivatizing steps in gas-liquid chromatography make such a system highly attractive to the analyst. The most frequently used methods of detection are fluorimetric (14,15) and electrochemical (5,6,(16)(17)(18)(19)27) ones.…”

mentioning

confidence: 99%

The Determination of Urinary Metanephrine and Normetanephrine by High Performance Liquid Chromatography with Ultraviolet Absorbance Detection

Tejral¹,

Nentwich²

1992

Journal of Liquid Chromatography

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43 B m , CSFR ABSTRACTThe sensitive and specific direct analysis of urinary normetanephrine and metanephrine (both free and conjugated) was achieved utilizing reversed-phase high performance liquid chromatography and W detection. The urine specimens were hydrolysed in a boiling water bath and treated with isoamyl alcoho1:toluene to eliminate interference from urinary pigments or related chemical compounds. The methoxyamines were isolated by the passage through a small ion-exchange column and then pre-concentrated by a rapid set of solvent (ethyl acetate:acetone) extractions before being injected into the chromatographic column.Detection was achieved with W absorbance detector at 280 nm and metanephrines were quantified by standard addition method. For both metanephrine and normetanephrine the standard curve was linear over the range of 15-300 pmol/L and practical lower detection limits were about 100 nmol/L for actual urine samples, which are not too different from those using electrochemical detector. Samples can be injected at 10-min intervals.The values for a patient with pheochromocytoma and for other patients are given.

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